Nausea, the sensation of having the urge to vomit, and vomiting, the emptying of the contents of the stomach through the mouth, may be caused by a variety of different reasons. Some common causes of nausea and vomiting are:

1. Gastroenteritis, commonly known as “stomach flu,” from bacterial or viral infections

2. Food poisoning

3. Overeating

4. Migraine headaches

5. Brain injury or concussions

6. Inner ear and balance disorders

7. Motion sickness

8. Hormonal imbalances, especially during the first trimester of pregnancy

9. Certain toxins, such as alcohol

10. Drugs, such as chemotherapy agents, for treating cancer